Revision in total knee arthroplasty: an analysis of 69 consecutive cases (sepsis excluded)

Purpose of the study We reviewed 69 consecutive cases of total knee arthroplasty revisions to an alyze the causes of failure. Material and methods Sixty-nine total knee arthroplasty revisions were required between 1990 and 1997 for non-septic failure. Five categories of failures were identified: 30 loosenings including 11 with an initial malposition (varus position of t he tibial component in 8 cases), 14 laxities (medial in 5, lateral in 5 and anteroposterior in 4), 11 stiff knees with no other clinical or radiologic al anomaly, 6 patellar failures (2 dislocations, 2 cases of excessive wear, 2 painful knees with a Freeman prosthesis), and 8 cases of painful knees w ith no other detectable anomaly. Results A three-phase reconstruction procedure was used after removing the failing TKA: 1) reconstruction of the tibia with replacement of lost bone, 2) recon struction of the femur with balanced flexion determining the size of the im plant, 3) balanced extension determining the distal/proximal position of th e femoral component. A "simple" sliding prosthesis was used in 16 cases, a modular reconstruction prosthesis in 40 cases and a hinge prosthesis in 13 cases. Mean follow-up for functional and radiographic assessment after revi sion surgery was 37 months (59 cases) with a minimum follow-up of 1 year. T he best outcome was observed in the "loosening", "laxity", and "stiffness" patients. Outcome was less favorable for the group "isolated pain" with IKS functional scores of 35.5 +/- 16 and 52.5 +/- 21. Discussion In 36 p. 100 of cases, TKA failure was related to a technical mistake (comp onent malposition, poor ligament alignment). In 33 p. 100, failure was pati ent related (multiple procedures, congenital hip dysplasia, rheumatoid arth ritis...). Outcome after revision TKA was less favorable than after primary TKA, particularly in case of painful knees with no other detectable anomal y. Conclusion Surgical revision of TKA must follow a rigorous procedure with a detailed p reoperative work-up. The decision for revision must not be made unless a pr ecise anomaly has been identified.